Automatic brake control device



1950 M. M. M. BILLON 2,517,078

AUTOMATIC BRAKE CONTROL DEVICE Filed Sept. 10, 1946 2 Sheets-Sheet 1 I 'INVENITOR. lla rcel Mame fiaumre 19421012 Aug. 1, 1950 M. M. M. BlLLON AUTOMATIC BRAKE CONTROL DEVICE 2 Sheets-Sheet 2 Filed Sept. 10, 1946 Patented Aug. 1, 1950 AUTOMATIC BRAKE CONTROL nnvrcr:

. Marcel Marie Maurice Billon, Besancon, France; assignor to 'iecalemm SocieteAnonyme; Banis France, a joint-stock company of France Application-September 10, 1946, Serial No sensor InsFrance Septembesl, 1945 Claims. 1 llhis.invention relates. to a method and a device for the. automatic. adjustment of brakes.

. The invention relates. .to a method. for the automatic adjustment of brakes. characterized. by the. feature. that the braking reactions oi two. difierently braised axles are. set in. opposition so. that said reactions are balanced. together.

during a period of normal braking. Releasing oi the brakes is. automatically controlled. when the balance of the reactions is destroyed. either because the braking power applied initiates stoppage at the most intensively braked axle which begins to stop thus causing a sudden and considerabl'e increase of the braking reaction, or on complete stopping of the same axle which causes an important decrease of the braking reaction, or on complete stopping of both axles which causes identical Braking reactions but which acts on the balance a different manner, said method making' it thus possible automatically to cease braking immediately before reaching the stopping limit or automatically to prevent complete stopplug.

The invention generally covers this method regardless of the devices used for carrying outthe same. However, the invention also covers device making itpossible to carry out said methocl in a particularly advantageous and efiifcaciousmanner. The method and. the devices used for attainin' the. above mentioned ohi'ects show the features which will appear from the following description more patticularly from the appended claims.

Devices. for the: automatic adjustment of the braking are shown. by way of. examples: in". the following. drawings, in which:

Figure: 1 is a diagrammatical sectional. View showing; the device: in. the balancing. position.

Figure 2 is: a. sectional view showing the device of. Figure- 1 the unbalanced position.

Figure 3- is a diagra-mmatical sectionalview of a modification showing a hydraulic device in the balancing. position, and

Figure 4 is a sectional view showing the. device of Figure 3111 the unbalanced position.

According to the method of the. invention the balancing operation. is effected through. anymechanical, hydraulic or other means for the brakiing reactions transmitted, on the one hand, by one of the connecting rods supporting the brake shoes of a more intensively braked axle and, on the other hand, by one of the connecting rods supporting the brake shoes of a less intensively braked axle.

It is known that. one: of. the particularities of braking. resides the increase. of the: stress trans.- mitted totheconnecting rods supporting the brake shoes at the very moment when the axle begins to stop;

This increase of the stress: which,. moreover, corresponds to an increase of the retarding. force applied to the. braked vehicles, arises when the bra-lied. wheel. begins. to slow down. It persists during the whole slowing down and then falls suddenly to.- a. verysmall value as soon as the wheel is completelystopped.

Owing to. this fact... the balancing of the. brakmg reactions transmitted by each connecting rod supporting the. brake shoesofi each axis is maintained during. the whole. timeof the normal. brake ing until. the. very. moment one ot the. axles stops.

When. the most-intensively braked axle is. stopped the sudden. increase. oil the stress trans.- mitted to the. connecting uodby the. brake. shoes destroys the. balance otthe. opposition. device which immediately reacts. upon. the braking reduction mechanisme Likewise, if one. oi the. wheels of the axles is completely stopped the value: of; the. sliding. reaction of said' wheel becomes negligible which. re.- sults, therefore in a. lack. of balance in the other direction,. thus. causing a reduction of the brak i'ng effect.

Owing to this fact the method also makes it possible to prevent complete stopping.

The balancing connection. can be. made by various means, more particularly by means of levers whichestablish from one connecting rod to the other aureverse. connectionratio with respect to the ratio of the braking rates of one and the other axle.

Figures 1 and 2 show afirst form. of execution oi the device used. for. carrying out the above described. method.

In said. device the wheels I. and. 2 of. a bogey are braked by the brake shoes 3 and 4 respec tively, the. respective. connecting rods. 5. and 6- of which are pivotally connected to. the ends of the lovers T' and 8 j'ournalled at 9' and In on the frame ll.

The ends of the lovers l. and. 8. are connected by the connecting rod [2 which can. act indi'fi'erently upwards or downwards upon. the valves [3 and M. which control the exhaust of the compressed. air line l-5' leading to the brake cylinder l6'..

The brake gears (not shown) from brake cylinden 16" are established so as to insure a braking 3 rate for the wheel I higher by a certain value than the braking rate applied to the wheel 2.

The right and left arms of the lever I and the right and left arms of the lever B are then established so as to insure equal and opposed reactions on the connecting rod I2. The device works in the following manner.

The balancing of the reactions being maintained until wheel I'begins to slow down, the valves I3 and I4 remain closed; at the moment when the braking value becomes such that wheel I begins to stop, the reaction upon the connecting rod suddenly increases; the balance is destroyed and the connecting rod I2 moves either downwards or upwards according-to the direction of the rotation of the wheels I and 2.

This displacement has for its efiect to displace one of the valves I3 or I4 from its seat which determines the emptying of the brake cylinder I6 until the tendency to stop ceases.

Since the forces acting upon the connecting rod I2are considerable, the diameter of the valves I3 and M can be large enough for insuring an almost instantaneous emptying of the brake cylinder.

Thus, the device limits the braking automati- =cally to the stopping valve.

The device can also prevent complete stopping in the following manner. If a defect in the working causes the complete stopping of the wheel I, l the reaction upon the connecting rod I2 changes its direction since the value of the sliding reaction becomes negligible. Owing to this fact, the connecting rod I2 immediately actuates the opposed valve. If the wheels I and 2 are stopped in succession, the sliding reactions of the wheels on the rails would become equal and, consequently, also the reactions transmitted to the connecting rods supporting the brake shoes.

Since the transmission lever arms of said reactions are unequal, there would be again a displacement of the connecting rod I2 and the opening of one or the other exhaust valve.

The second form of execution of the invention shown in Figures 3 and 4 shows a similar automatic regulation device but of the hydraulic type.-

In said device they connecting rods 5 and 6 are connected with the pistons' I1 and I8 moving in the cylinders I9 and 20 respectively which are hydraulically connected by the lines 2I and 2| to the right and left side of a balancing cylinder "22 in which a piston 23 slides.

' The piston rods 24 and 25 control the displacement from their seats of the valves 26 and 2'! arranged in exhaust lines 28 and 29 of the brake cylinder 30.

I The exhaust valves 26 and 2! are maintained closed by springs 3! and 32.

The sections of the pistons I! and I8 are established in the reverse ratio of the braking rates applied to the axles I and 2 respectively.

The device works as follows.

l'So long as. the braking remains normal, the reaction transmitted by the connecting rods 3 and 5 remains higher than the reaction transmitted by the connecting rods 4 and 6. Butas the section of piston I1 is smaller than the section of piston I8, according to the ratio of the reactions the pressure is the same on the right and left faces of balancing piston 23.

When stopping occurs on wheel I, which is the most intensively braked, the reaction transmitted by the connecting rod 5 suddenly increases.

' The piston 23 moves, carrying'with it the piston 4 rods 24 and 25, which has for its effect to lift one of the exhaust valves 26 or 21 until the stopping has ceased.

If, in spite of the opening of one of the exhaust valves, a total stopping of wheel I occurs the sliding reaction of wheel I on the rail instantaneously falls to a very small value.

The device works in the opposed direction thus causing the opening of the second valve.

Finally, if both wheels I and 2 are stopped the connecting rods 5 and 6 transmit equal reactions to the pistons I1 and I8.

The pressure difference on both faces of piston 23 which is a function of the ratios of the sections of the pistons, causes the lifting of one of the exhaust valves 29 or 30.

I claim:

1. In a device for automatic adjustment of braking power, two axles, means for differently braking said axles, a brake cylinder, a first exhaust valve for the brake cylinder, a second exhaust valve for the brake cylinder, a connecting rod between both valves controlling the opening of one or the other valve according to the direction of its displacement, a first rocking rod connecting the braking means of the first axle with the valve control rod, a second rocking rod connecting the braking means of the second axle with the valve control rod, said second rocking rod acting on the valve control rod in the re-v verse direction to said second rocking rod.

2. In a device for automatic adjustment of braking power, two axles, means for differently braking said axles, a brake cylinder, a first exhaust valve for the brake cylinder, a second exhaust valve for the brake cylinder, a first hydraulic piston controlled by the braking means of the first axle, a second hydraulic piston controlled by the braking means of the second axle, a balancing piston one of the faces of which is controlled by the first hydraulic piston while the other face is controlled by the second hydraulic piston, a rod controlled by the balancing piston mounted between both valves and controlling the opening of one or the other valve according to the direction of its displacement. "3. In a device for automatic adjustment of braking power, two axles, means for difierently braking said axles, a brake cylinder, a first exhaust valve for the brake cylinder, a second exhaust valve for the brake cylinder, a first hydraulic piston controlled by the braking means of the first cylinder, a second hydraulic piston controlled by the braking means of the second cylinder, the ratio between the surfaces of both pistons being equal to the ratio between the braking reactions of both axles, a balancing piston one of the faces of which is controlled by the first hydraulic piston while the other face is controlled by the second hydraulic piston, a rod controlled by the balancing piston mounted between both valves and controlling the opening of one or the other valve according to the direction of its displacement.

4. In a device for automatic adjustment of braking power, two axles, means for differently braking said axles, a balancing device for balancing the braking reaction of both axles, a brake cylinder, means connecting said cylinder and braking means, means for setting the brake: cylinder on exhaust, and connecting means be tween the balancing device and the exhaust setting means for controlling said exhaust means responsive to movement of the balancing device.

2,517,078 5 6 5. In a device for automatic adjustment of REFERENCES CITED braking power, two axles, means for difierently braking said axles, a brake cylinder, exhaust valves for the brake cylinder, a connecting rod The following references are of record. in the file of this patent:

controlling said valves, a first rocking rod con- UNITED STATES PATENTS necting the braking means for the first axle to Number Name Date the valve control rod, and a second rocking rod 214,337 Westinghouse Apr. 15, 1879 connecting the braking means for the second 1,122,225 Abel Dec. 22, '1914 axle to the valve control rod, said first and sec- 2,179,399 Browall Nov. 7, 1939 0nd rocking rods acting upon the valve control 10 W a, rod in mutually opposed directions. PATENTS Number Country Date MARCEL MARIE MAURICE BILLON. 7,589 Great Britain A. D. 1908 329,240 Italy Sept. 3, 1935 

